Background Foot misalignments may contribute to development of sports injuries. Some evaluation protocols of foot alignment are not practical, have poor reliability and doesn't reflect functional foot behaviour. We propose a new measurement procedure to solve these problems. We also introduce the measure of the alignment of shank relative to shank-forefoot alignment (SFA) that may be practical to assess the combined rearfoot and forefoot alignments.
Objective to develop a practical and reliable foot alignment measure.
Design observational cross-sectional.
Setting all testing took place in the Minas Tênis Club and Sports Injury Prevention and Rehabilitation Laboratory – LAPREV in youth and elite sports.
Participants 75 females and 125 male (mean+SD age, 15.6+3.8; height, 151.1+62.8; body mass, 64.53+14.9) athletes were evaluated in this study (n=200). Participants with a history of congenital deformity or lower-extremity surgery in the previous 6 months were excluded.
Assessment: Shank bisection and four calcaneus marks were drawn according to the standardised parameters. A metal rod was fixed under the forefoot, the ankle was actively positioned at 90° of dorsiflexion and a picture was taken. SIMI motion 2D was used to measure the rearfoot (relative to shank), forefoot (relative to rearfoot) and SFA angles.
Main outcome measurements rearfoot, forefoot and SFA angles.
Results The Intraclass Correlation Coefficient (ICC) intratester was 0.89; 0.91 e 0.93 and intertester was 0.82; 0.91 e 0.90 (rearfoot, forefoot and SFA respectively). The means for each foot alignment were −1.83+3.3 (rearfoot), 16.25+8.9 (forefoot) and 13.9+2.6 (SFA). The agreement (ICC) of the sum of rearfoot and forefoot values with SFA was 0.98.
Conclusion SFA reflects the sum of rearfoot and forefoot alignments, which supports the use of this measure. This protocol is reliable and it is possible to assess one athlete in proximally 5 min. Thus, these measures can be used in preseason assessments of injury risk factors in athletes.